Function dustem_plugin_modify_dust_pol, key=key, val=val, scope=scope,paramtag=paramtag,help=help

;+
; NAME:
;    dustem_plugin_modify_dust_pol
; PURPOSE:
;    Produces stokes emission parameters for the dust and synchrotron components
; CATEGORY:
;    DUSTEM Wrapper
; CALLING SEQUENCE:
;    dustem_create_stokes(st,key=key,val=val)
; INPUTS:
;
; OPTIONAL INPUT PARAMETERS:
;    key  = input parameter number
;    val  = input parameter value
; OUTPUTS:
;    out = array containing the stokes emission parameters associated to the dust/synchrotron component or a concatenated version for both
; OPTIONAL OUTPUT PARAMETERS:
;    None
; ACCEPTED KEY-WORDS:
;    help                  = if set, print this help
; COMMON BLOCKS:
;    None
; SIDE EFFECTS:
;    None
; RESTRICTIONS:
;    The dustem fortran code must be installed
;    The dustem idl wrapper must be installed
; PROCEDURE:
;    This is a dustem plugin
;-

IF keyword_set(help) THEN BEGIN
  doc_library,'dustem_create_stokes'
  out=0.
  goto,the_end
ENDIF


paramtag=['p','Psi (deg)']

IF  ptr_valid((*!dustem_fit).CURRENT_PARAM_VALUES) THEN BEGIN
    p_di=(*(*!dustem_fit).CURRENT_PARAM_VALUES)
    
ENDIF ELSE BEGIN
          p_di=(*(*!dustem_fit).PARAM_INIT_VALUES)    
      ENDELSE 
          
st=dustem_run(p_di)      
;stop

psi=0.
smallp=1.
IF keyword_set(key) THEN BEGIN 
  ind1=where(key EQ 1,count1)
  ind2=where(key EQ 2,count2)
  IF count1 NE 0 THEN smallp=val[ind1[0]] ; setting smallp from pd
  IF count2 NE 0 THEN psi=val[ind2[0]] & !dustem_psi = psi ; setting psi from pd.  !dustem_psi here helps for the plotting.   
ENDIF


fact = 1.e4*(*!dustem_HCD)/(4.*!pi)/(3.e8/1.e-6/((st.polsed).wav))*1.e20/1.e7
P=((st.polsed).em_tot)*fact
I=((st.sed).em_tot)*fact


Nwaves=(size(I))[1]

frac=P/I*smallp
tes=where(finite(frac) eq 0)
frac(tes)=0.


polar_ippsi2iqu,I,Q,U,frac,replicate(psi,Nwaves) 

out=fltarr(Nwaves,3)

out[*,0]=I
out[*,1]=Q
out[*,2]=U

scope='REPLACE_POLSED'

return, out

the_end:


end